Synchronous buck converters, primarily used in step-down power supply circuits, typically include two switching field effect transistors (FETs) and a series inductor to permit digital, rather than analog, control of the FETs which either supply current into the inductor or draw current back from the inductor. Compared to analog power supplies, the synchronous buck converter with FET switching transistors are small and use very little overhead current. Thus they are often used for mobile electronic devices. Since space is an important consideration in such devices, the size of synchronous buck converters is important in the marketplace.